This invention relates to wheel covers for motor vehicle road wheels and to an assembly comprising secondary lug stud nuts for attaching such covers to the wheels.
Numerous retention means and systems are known to the skilled of the art for retaining a wheel cover to a motor vehicle wheel. It frequently is desirable to provide a wheel cover with a retention system which does not rely on any particular contour of the wheel's surface to retain the wheel cover in position. Wheel cover retention systems which rely on a frictional engagement with a radially inward facing annular surface of the rim portion of a wheel or the lip flange of such rim portion are known. Such retention means, generally located at the outer periphery of the wheel cover, do not positively lock the wheel cover to the wheel and, in addition, typically prevent rotation of the wheel cover outer periphery relative to the vehicle wheel. Also, such peripheral retention means involve considerable manufacturing complexity and cost, typically requiring the use of metal bands, metal retention clips, etc. Also, the wheel cover must be of adequate weight and structure to afford a durability requisite to withstand the forces applied to the wheel cover to engage it with the vehicle wheel.
Other wheel cover retention systems are known which relay on the lug stud nuts which retain the wheel to the vehicle axle. Such systems, however, generallly require the use of a non-standard lug stud nut adapted to facilitate engagement with the wheel cover. This involves both a cost and complexity penalty for such retention systems. In addition, retention means of this type typically are disadvantageous in that the vehicle wheel must be mounted onto the lug studs and held in position without benefit of the lug stud nuts, while the much more fragile wheel cover is mounted over the wheel onto the lug studs. Not only is this frequently a difficult operation to coordinate, but it presents risk of damage to the fragile wheel cover while the lug stud nuts are assembled, since during this time the heavy wheel is held in position by applying considerable pressure against the outer surface of the wheel cover overlaying the wheel.
It is an object of the present invention to provide a wheel cover and a wheel cover assembly employing a retention means which does not require engagement with the vehicle wheel at the outer periphery of the wheel cover and which does not require non-standard lug studs or lug stud nuts to mount the wheel. It is a further object of this invention to provide a retention means whereby such wheel cover can be mounted separately and independently to the vehicle wheel following mounting of the wheel. Additional objects and advantages of the invention will be understood from the following description.